Mitochondria are dynamic organelles of eukaryotic cells which fulfill numerous essential functions, including, ATP-generation, calcium signaling, phospholipid metabolism and apoptosis. A fundamental pathway utilized by cells to ensure mitochondria meet cellular demands is to govern the delicate balance between fusion and fission in the mitochondrial network. Mitochondrial dynamics are tightly regulated processes that occur in response to the cell environment or cellular differentiation. A disturbance of these dynamics, often observed under stress or pathologic conditions, causes mitochondrial fragmentation which can ultimately lead to cell death. Current methods for detecting mitochondrial dysfunction rely on the use of assays such as PCR and specific mutation analysis. Assaying disturbances in the dynamic regulation of the mitochondrial network is difficult requiring specialized cellular imaging techniques, which generally can be time-consuming and costly.
OMA1 is an important regulator of mitochondrial dynamics involved with normal quality control of the mitochondrial network. OMA1 expression is induced with stress to mitochondria and increased OMA1 activity promotes mitochondrial fragmentation. Current methods for assaying OMA1 activity utilize an indirect method through western blotting by determining the proteolytic processing status of the inner mitochondrial membrane-localized protein, dynamin-related GTPase optic atrophy type 1 (OPA1). However, OPA1 can be processed by multiple proteases, complicating the analysis of OMA1 activity.
Thus, there is a need for a technology which allows for the detection of OMA1 activity in a sensitive, direct and efficient manner. Additionally, there is a need for high throughput screening methods useful for drug discovery and detection of diseases associated with mitochondrial dysfunction.